Electronic apparatuses, such as portable computers, may be connected to external apparatuses for function extension. The external apparatuses may be, for example, port replicators, docking stations or the like. An external apparatus comprises a ground electrode. The ground electrode projects from a surface on which the portable computer is mounted. The portable computer comprises a conductive member to be connected to this electrode.
A shield layer made of copper plating or the like is formed on an inner surface of the casing of the portable computer. The shield layer prevents an electromagnetic wave generated by circuit parts or the like in the casing from passing through and leaking out of the casing. Further, the shield layer prevents an external electromagnetic wave from adversely affecting the circuit parts in the casing.
The conductive member is electrically connected to the shield layer in the casing. The conductive member is connected to the ground electrode provided in the external apparatus. As a result, the potential of the shield layer of the portable computer becomes equivalent to that of the electrode of the external apparatus.
A leaf spring is used as the conductive member so that the conductive member is stably connected to the shield layer. Preferably, the leaf spring should easily be attached to the casing.
Jpn. Pat. Appln. KOKAI Publication No. 8-293335 discloses a ground spring attachment structure, in which a ball-shaped projection and a wedge-shaped bump portion are provided on a conductive body. The ground spring is provided with two holes respectively corresponding to the ball-shaped projection and the wedge-shaped bump portion. Utilizing the elasticity of the ground spring, the ball-shaped projection and the wedge-shaped bump portion are respectively fit in the two holes of the ground spring. Accordingly the ground spring is attached to the conductive body. Thus, the ground spring is easily attached to the conductive body without secondary working, such as screwing.
On the other hand, as described above, the electrode of the external apparatus is connected to the conductive member of the portable computer. To prevent the conductive member from deviating from a predetermined position or being removed by external force, the conductive member should desirably be firmly connected to the casing.
To firmly connect the conductive member to the casing, the conductive member may be provided with a positioning hole and the casing may be provided with a positioning pin, which is inserted through the hole. The conductive member and the casing are welded by melting the pin.
If the conductive member and the casing are welded by melting the positioning pin, the conductive member is firmly fixed to the casing. However, since the number of processes is increased by the melting of the pin, the time and cost for the production is increased.
From a different viewpoint, the portable computer is decomposed after discarded. Resources such as metals contained are recovered from the parts of the decomposed portable computer. However, if the conductive member is welded to the casing by melting the positioning pin, the conductive member made of a metal cannot be easily removed from the casing made of a synthetic resin.
To easily remove the conductive member, the ground spring attachment structure described above may be adopted. In the ground spring attachment structure, a ground spring for electrically connecting a pair of conductive members facing each other is attached to one of the conductive members. The ground spring attachment structure is not intended for the conductive member having a part exposed out of the casing.
Further, the conductive member connected to the electrode of the external apparatus includes a part which is exposed out of the casing and a part which is electrically connected to the shield layer inside the casing. The part exposed out of the casing has a short length for aesthetic purposes. The part connected to the shield layer inside the casing has a long length to assure the adhesion to the shield layer. The ground spring attachment structure is not intended for the conductive member having such a shape. Therefore, the ground spring attachment structure cannot be easily applied directly to the conductive member, which is connected to the electrode of the external apparatus.